Conventionally, there are provided various types of telecommunication systems for use in telephone terminal devices such as analog cellular systems and digital cellular systems that are known as personal digital cellular telecommunication system (PDC) and personal handyphone system (PHS). In response to incoming calls, telephone terminal devices that are carried by users produce incoming call sounds to notify users of reception of incoming calls from calling parties. As incoming call sounds, telephone terminal devices produce beep sounds, which are offensive to ears of users. Recently, telephone terminal devices are developed to produce musical tones representing melodies of musical tunes, which are substituted for conventional beep sounds. Incidentally, the aforementioned musical tones are called incoming call melody sounds.
Telephone terminal devices that are capable of producing incoming call melody sounds each have a music playback section for the purpose of reproduction of music data representing a melody of a musical tune which is produced as incoming call melody sound. Such a music playback section can be used for the other purpose of generating musical tone signals, other than the purpose of notifying the user of incoming calls. That is, musical tone signals are used to meet various types of uses such as generation of background music (BGM) and hold sound as well as playback of music for appreciation. Hence, musical tone signals must be specifically processed to suit the aforementioned uses. In order to use musical tone signals for generation of incoming call melody sound, for example, musical tone signals are sharpened to allow the user hearing incoming call melody sound even in noisy environment. In order to cope with various types of uses, it is preferable that various types of music data suited for various types of uses are provided for telephone terminal devices. That is, various types of use-specified music data are installed in telephone terminal devices in advance.
To cope with different uses, it is required that various types of music data regarding the same musical tune are stored in telephone terminal devices. This raises a necessity to increase storage capacities for storing multiple music data in telephone terminal devices. However, recent telephone terminal devices, particularly portable telephones, must be downsized in weight and size. Due to the downsizing of telephone terminal devices, it is difficult to provide relatively large spaces for large-capacity storage. Even though telephone terminal devices allow installation of large-capacity storage, there is a problem that the total manufacturing cost is increased because of the installation of large-capacity storage.
It is an object of the present invention to provide a telephone terminal device that is capable of reproducing musical tone signals for different uses with a reduced storage for storing music data.